A. Field of Invention
This invention pertains to the art of methods and apparatuses for piering the foundation of a building.
B. Description of the Related Art
It is known in the art to drive a piling or a pier into the ground to support the foundation for a building. It is also known to raise a sunken foundation where the foundation has sunk due to settling of the ground. Typically, piering members, in predetermined sections having a characteristic length for example of three (3) or four (4) feet, are driven into the ground one directly on top of the other. Couplers may be used connect each subsequent pier. The piering members are then added and driven consecutively into the ground to the point of refusal. The foundation is then built upon or fixed to the piering members for support of the foundation. In the case of raising a sunken foundation, the piering members may be fastened to the foundation via bolts or the like.
One aspect of the piering members or pilings is that for a given diameter of a support tube, the piering members can only support weight proportionate to the diameter of the tube. This may result in the need to install additional piering members or piering members having a larger cross sectional diameter, adding to the cost of the materials. It would be beneficial to have a piering member that expanded its diameter after having been inserted into the ground to increase the surface area and amount of support for a given foundation.